SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4f4a553e966699ead9a85e2b26ceb2871b587dbb9b5e40d818abb7f7d759e5c' 
  AND token = 'qmVH+y9638I+EE4MHKv070LRx3Mpb/WFpPpddKui5cE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables